Microlithography is used for the production of microstructured components, such as, for example, integrated circuits or LCDs. In general, the microlithography process is carried out in what is referred to as a projection exposure apparatus having an illumination system and a projection objective. Generally, the mask (commonly referred to as a reticle) is illuminated by the illumination system, and the image of the mask is projected by the projection objective onto a substrate (for example a silicon wafer). Typically, the substrate is coated with a light-sensitive layer (for example photoresist) which is arranged in the image plane of the projection objective so that the mask structure is transferred onto the light-sensitive coating on the substrate, generally reduced by a factor of 0.25.